Japanese Patent Application No. 63650/2001 filed on Mar. 7, 2001, is hereby incorporated by reference in its entirety.
This invention relates to a wiring board and a fabricating method thereof, a semiconductor device and a fabricating method thereof, a circuit board and an electronic instrument.
A form that electrically connects both surfaces of a semiconductor chip by boring penetrating holes in the semiconductor chip, forms an insulating film and then forms either wet or dry an electrically conductive film, or filling penetrating holes with molten solder is known. Since this method eliminates the necessity for disposing wires, a compact semiconductor device can be acquired even when a plurality of semiconductor chips is stacked one upon another.
However, the process step of filling penetrating holes with a conductive material is often time consuming and troublesome. A method that forms a film by means such as photolithography and renders the resulting film electrically conductive needs a large number of process steps, a long time and a high cost of production. A method of filling penetrating holes of a wiring board with a conductive material is also known, but the method needs a long time and troublesome procedures.
According to a first aspect of the present invention, there is provided a method of fabricating a semiconductor device comprising the steps of:
providing a conductive material to an open end of a penetrating hole penetrating through at least a semiconductor element, on the side of a first surface of the semiconductor element; and
melting the conductive material to make the conductive material flow into the penetrating hole,
wherein the conductive material is made to flow into the penetrating hole in a state that an atmospheric pressure on the side of a second surface of the semiconductor element opposite to the first surface is lower than an atmospheric pressure on the side of the first surface.
According to a second aspect of the present invention, there is provided a method of fabricating a stacked type semiconductor device comprising the steps of:
forming a plurality of semiconductor devices each of which is formed by: providing a conductive material to an open end of a penetrating hole penetrating through at least a semiconductor element, on the side of a first surface of the semiconductor element; melting the conductive material to make the conductive material flow into the penetrating hole; and causing the conductive material to flow into the penetrating hole in a state that an atmospheric pressure on the side of a second surface of the semiconductor element opposite to the first surface is lower than an atmospheric pressure on the side of the first surface;
stacking the plurality of the semiconductor devices; and
electrically connecting the semiconductor elements of the stacked semiconductor devices through the conductive material.
According to a third aspect of the present invention, there is provided a semiconductor device or a stacked type semiconductor device fabricated by any of the above methods.
According to a fourth aspect of the present invention, there is provided a semiconductor device comprising:
a semiconductor element having a pad and a penetrating hole penetrating through the pad and the semiconductor element; and
a conductive material that is provided in an area including an inner surface of the penetrating hole and is electrically connected to the pad, wherein part of the conductive material forms a bump protruding from a surface of the semiconductor element opposite to a surface having the pad.
According to a fifth aspect of the present invention, there is provided a stacked type semiconductor device comprising a plurality of stacked semiconductor devices each of which includes:
a semiconductor element having a pad and a penetrating hole penetrating through the pad and the semiconductor element; and
a conductive material that is provided in an area including an inner surface of the penetrating hole and is electrically connected to the pad,
wherein part of the conductive material forms a bump protruding from a surface of the semiconductor element opposite to a surface of the semiconductor element having the pad; and
wherein the semiconductor elements of the stacked semiconductor devices are electrically connected through the conductive material.
A circuit board according to a sixth aspect of the present invention comprises the semiconductor device or the stacked type semiconductor device described above.
An electronic instrument according to a seventh aspect of the present invention comprises the semiconductor device or the stacked type semiconductor device described above.
According to an eighth aspect of the present invention, there is provided a method of fabricating a wiring board comprising the steps of:
providing a conductive material to an open end of a penetrating hole penetrating through at least a board, on the side of a first surface of the board; and
melting the conductive material to make the conductive material flow into the penetrating hole,
wherein the conductive material is made to flow into the penetrating hole in a state that an atmospheric pressure on the side of a second surface of the board opposite to the first surface is lower than an atmospheric pressure on the side of the first surface.
A wiring board according to a ninth aspect of the present invention is fabricated by the above described method.